# Orbital character effects in the photon energy and polarization dependence of pure C60 photoemission

## TL;DR

This study reveals how photon energy and polarization influence the photoemission of C60 molecules, linking these effects to orbital character and molecular orientation, with implications for electronic structure analysis and device applications.

## Contribution

It provides a detailed analysis of photon energy and polarization effects on C60 photoemission, highlighting the orbital character influence and molecular orientation effects.

## Key findings

- Photon energy and polarization significantly affect C60 photoemission intensities.
- Orbital character determines the photoemission response to light polarization.
- Molecular orientation is locked at low temperatures, affecting electronic properties.

## Abstract

Recent direct experimental observation of multiple highly-dispersive C$_{60}$ valence bands has allowed for a detailed analysis of the unique photoemission traits of these features through photon energy- and polarization-dependent measurements. Previously obscured dispersions and strong photoemission traits are now revealed by specific light polarizations. The observed intensity effects prove the locking in place of the C$_{60}$ molecules at low temperatures and the existence of an orientational order imposed by the substrate chosen. Most importantly, photon energy- and polarization-dependent effects are shown to be intimately linked with the orbital character of the C$_{60}$ band manifolds which allows for a more precise determination of the orbital character within the HOMO-2. Our observations and analysis provide important considerations for the connection between molecular and crystalline C$_{60}$ electronic structure, past and future band structure studies, and for increasingly popular C$_{60}$ electronic device applications, especially those making use of heterostructures.